Automatic and semiautomatic telephone system



Aprii 5, E1932. E. P. e. WRIGHT AUTOMATIC AND SEMIAUTOMATIC TELEPHONE SYSTEM Filed Jan. 23, 1950 2 Sheets-Sheet V EfiMOHD PG. WREGHT BY INVENTOR ATTORNEY April 5, 1932. E. P. e. WRIGHT AUTOMATIC AND SEMIAUTOMATIC TELEPHONE SYSTEM Filed Jan. 25, 1930 2 Sheets-Sheet I T HI m .v N H v G Saw M N m h mMJWY a m .A mm W munm m #w mm W DDHDUUDDDD .ln VM )7 A ,W b mm 1 m 1 S m 53 W M Q I E w. J 3 E v $2333 I B fig N N rziiiwfiiica mu W m A m MEN a lnl sgw l..| i 5...@ W wfiw ii lfi w $433 34 m @E a am 1 1 b w I m riw F #53151: 1w l k m L 1 j W Wu G E W [NW KN iiii .ZXIIQH T L Patented Apr. 5, 1932 STATES PAT r Price ESMOND PHILIP GOODWIN WRIGHT, OF ALDWYCH, LONDON, ENGLAND, ASSIGNOR T INTERNATIONAL STANDARD ELECTRIC CORPORATION, OF NEW YORK, Y.

AUTOMATIC .AND SEMIAUTOIEATIG TELEPHONE SYSTEM Application filed January 23, 1930, Serial No. 422,802, and in Great Britain February 12, 1929.

of control circuits common to a plurality of switches. It is the object of this invention to apply this method of control to the special switches which are used by a trunk operator in extending a trunk-offering connection to a trunk or subscrlbers line requlred for a trunk call. These switches usually comprise a trunk-offering distributor switch which in response to two digits selects without any hunting operation a trunk offering final switch giving access to the wanted trunk or line, the distributor switch being arranged to test the condition of such final switch and transmit a busy signal to the trunk operator if it is engaged. The trunk offering final switch in response to two further digits selects no the wanted trunk or line extends connection thereto without making any test of its condition. a

According to the present invention a control circuit which is adapted to be operatively as associated with any one of a plurality of trunk-offering distributor switches to the ex-' clusion of the others, in response to impulses transmitted by an operator controls the selective operation of a predetermined distributor 4O switch.

In accordance with another feature of the invention a control circuit which is adapted to he operatively associated with any one of a plurality of trunk offering final selectors,

in response to impulses transmitted by an engaged operator controls the selective operation of a predetermined one of said final selectors.

The invention will be better understood from the following description taken in con junction with the accompanying drawings in which Figure 1 shows above the broken line a trunk-offering distributor switch of ,the single-motion step-by-step homing type, and below the brokenline a control circuit common to a group of distributor switches and comprising a group marking auxiliary switch 1T0 and a unlts marking auxiliary switch lUO.

Figure 2 shows above the broken line a ing a tens marking switch QTC and a units .marking switch QUC.

The trunk offering distributor switches terminate in jacks at trunk offering operators positions, the idle conditions of said distributors being indicated by a supervisory lamp. To set up a trunk offering call the operator plugs into the jack of an idle distributor Fig. 1 and completes a circuit over the test wire for relay 1K of the distributor switch and relay 12 of the distributor control circuit from ground on the sleeve of the operators plug over the test wire, contacts 1 of relay 1H normal, both windings of relay 1K in parallel, both windings of relay 12 to battery. Both these relays operate and relay 1K completes a circuit for relay 11 from battery through the winding of relay 11, contacts 2 of relay 1K operated, contacts 3 of relay 1H normal, over the loop to the operator and back over the positive wire to the contacts 2 of relay 1H normal to ground. Relay 12 at contacts 1 open the circuit over its non-inductive winding to mark the control non-selectable: the circuit over this winding will also be opened at wipers 1UC2 and 1TC2 if either of the marking switches are not in their normal position. Relay 11 completes the obvious circuit for relay 14. Contacts 1 of relay 14 extends ground through contacts 1 of relay 1K to the test wire and lights the supervisory lamp SL on the operators positions. Relay 11 responds to impulses but the relay 14 being of the slow to release type does not fall back during the impulsing and a circuit is therefore completed at each of the impulses of the first series, from battery through the magnet 1TC, contacts 2 ol relay 15 normal, winding of relay 13, contacts 2 of relay 14 operated, contacts 2 of relay 17 normal, contacts 1 of relay 11 normal to ground. Relay 13 is also of the slow to release type and remains energized throughout the series of impulses. As soon as relay 13 operates a circuit is completed from the magnet S of the distributor switch through contacts 4 of relay 1H normal. interrupter springs,

contacts 3' of relay 1K operated, contacts 1 of relay 16 normal, and contacts2 of relay 13 operated to ground. The magnet S will continue stepping until the control wiper C reaches a contact marked by the ground from contacts 4; of relay 16 normal, the wiper lTCl of the switch ITC' to thecontrol bank contact and wiper C, when the relay 16 operates over contact 5 of relay 1K operated,

contacts 3 of relay 16 normal, to'the winding of relay 16 and battery. lVhen relay 16 operates it opens the circuit of magnet S- at contacts 1 but does not lock up until relay 15 is operated, hence the. distributor switch cannot step ahead of the dialled impulses as registered in switch 1TC. A circuit is also closed from one winding of relay 15 through contacts3 of relay 15 normal, contacts 1 of relay 13 operated, to ground causing this relay to operate its light spring of contacts 1. At the completion o'l 'the first series or impulses, relay 13 restores and the short circuit across the second winding ofrelay 15 is removed permitting this relay to operate fully through both windings in series, contacts 1 of relay 15 operated, contacts 3 of relay 14; operated to ground. Contacts 2 of relay 15 switch the impulsing circuit from the magnet lTC to the magnet lUC in preparation for the second'series of impulses. Contacts 4: of relay 15 complete the circuit for the magnet S of the distributor switch from battery, through contacts d of relay 1H normal, the inerrupter springs, contacts 3 of relay 1K operated, contacts 1 of relay 16 normal, contacts 4 of relay 15 operated to ground. 'At the same time a testing circuit is prepared from battery through the winding of relay 16 through contacts 3 of relay 16 normal, contacts 5 of relay 1K operated to the control wiper C. At the same time a marking ground is placed on one of the control bank contacts through contacts 1 of relay 16 normal and a wiper and contact ofbank 1TC1 of the switch lTC. The bank contact of the distributor which is marked in this way is dependent upon the position of the switch lTC which is set by the first set of impulses.

When the distributor switch reaches the marked contact relay 16 operates closing for itself a locking circuit through contacts 6 of relay 15 and contacts 2 of relay 16 to ground at contacts 3 of relay 14L operated. Belay 16 opens the driving circuit of the distributor switch at contacts 1. The second set of impulses are repeated over a circuit similar to that already described to magnet lUC, the relay 13 being operated as before. Relay 17 has a circuitfor itslower winding through contacts 6 of relay 17 normal, contacts 3 of relay 15-ope-rated, contacts 1 of relay 13 operated, to ground, and when at the completion of the: series of impulses relay 13 restores, the short-circuit is removed from the second upper winding of relay 17 and that relay operates "fully through both windings in series,-contacts 5 of relay 17, contacts 3 of relay '14, to ground. Contacts 1 of relay 1'? opening the energizing circuit of relay 19 which was operated when relay 1'5 operated from battery through the noninductive winding, contacts 1' of relay 17 normal, contacts 5 of relay 15 operated, contacts 2 of relay 18 normal, the-inductive windingot relay 19 to ground at contacts 3 of relay 14 operated. Relay 19, however, provides a locking circuit through contacts '2 ofrelay 19 and does not, therefore, release when relay 17 operates. Contacts 2 of relay 1'7 open the impulsing circuit to prevent any further impulses being received by the switch lUC, contacts 3 of relay 17 recomplete the stepping circuit for the distributor through contacts 101 relay 16' operated contacts 3 of relay 17 operated, contacts 1 of relay 18 normal, to-ground. Vvhen the relay 16 operates due to the first marking-operation of the distributor a second test circuit is prepared from relay 18, through contacts 3 of relay 16 operated, contacts 5 of relay 1K operated to the control wiper C. A ground potential is placed on the appropriate control bank contact through contacts 4 of relay 1-6 operated, contacts 7 of relay 17 operated, contacts 4 of relay 19 operated, wiper and contact oi bank 1UC1 of the switch lUC. When the distributor switch reaches the correct set of terminals relay 18 operates opening thedriying circuit at contacts 1. Contacts 2 oi relay 18 open the locking circuit of relay 19 and closes a circuit through contacts 3 of relay 19 operated, contacts l of relay 1K operated through a winding of the relay 1H to the test wire to the final selector which will be characterized by a battery potential it that circuit is free. This battery potential will maintain relay 19 in its operated con dition and cause the operation of relay 1H.

Belay 1H switches through the negative and positive wires at contacts 3 and 2 respectively, contacts 1 open the circuit of relay 1K and extend the test wire to the test wiper T. Contacts 4 of relay 1H open the circuit of the distributor magnet S and contacts 6 of relay 1H closes a locking circuitfor that relay through its second winding to the test wire. The circuit for relay 12 is also opened when the circuit of relay lK'is opened by contacts 1 of relay 1H. Relay 11 is disconnected at contacts 2 and 3 of relay 1H relay 11 in turn opens the circuit for relay 14 which releases after a perioc. Relay 14 opens the circuit for relays 15, 16, 17 and 19 and these relays open the circuit of relay 18. A homing circuit is provided for the switch 1UC through its wiper and oil-normal bank 1UC3 to contacts 3 of relay 14 normal and when this switch reaches home a homing circuit is completed for the switch lTC through the home contact of wiper 1UC3 of the switch lUC and the oft-normal bank 1TC3.

Should it happen that the offering final is not free there will be no battery potential on the test wire and relay 19 will release thereby opening the circuit of relay 18 at contacts 4 of relay 19. A busy tone will be applied to the negative line from the lead BT through contacts 1 of relay 19 normal, the tone condenser and contacts 1 of relay 17 operated.

When the operator releases, ground is removed from the test wire and relay 1H restores. A circuit is then completed for the distributor magnet S through contacts 4 of relay 1H, interrupter springs, contacts 3 of relay 1K, wiper and oft" normal bank N to ground causing this switch to return to its home position.

As already described the offering final circuit Fig. 2 is seized over the test wire on which a ground potential is placed by the offering distributor and distributor control which'op crates relay 2K and relay 22 through contacts 1 of relay 2H normal; relay 22 is provided with a second and non-inductive winding the circuit of which extends over normal position contacts and wipers of the banks 2UC2 and 2TC2 of the'units and tens switches and which is opened at contacts 1 of relay 22 when that relay operates, or is opened when either of the switches are off-normal to mark the control busy. Relay 2A operates over the loop circuit and completes the obvious circuit for relay 2B which is of the slow-to-release type. When the operator impulses an impulse circuit is completed from ground. contacts 1 of relay 2A normal, contacts 1 of relay 2B operated, contacts 1 of relay 2K operated, contacts 1 of relay 27 normal, winding of relay 23, contacts 1 oi relay 25 normal, to the magnet 2TC and battery. The tens marking switch therefore, steps in accordance with the impulses dialled. Relay 23 which remains operated during the impulses causes the partial operation of relay 25 through one winding and contacts 5 of the latter relay and contacts 1 of relay 23 operated. When relay 23 restores, relay 25 operates fully through both windings in series, contacts 4 of relay 25 operated, contacts 2 of relay 22 operated, to ground. Relay 25 transfers the impulsing circuit to the magnet 2UC and completes the driving circuit for the final selector magnet 28 through its interrupter springs, contacts 2 of relay 2H normal, contacts 2 of relay 2K operated, contacts 1 of relay 26 normal, contacts 20f relay 25 op erated, to ground. Contacts 6 of relay 25 extend the marking ground from contacts 4 of relay 26 to the wiper 2TC1 of the switch 2TC and through the bank contact of that switch to a certain bank contact of the offering final. When the final reaches this position the ground is extended through the Wiper C, contacts 4 of relay 2K operated, contacts 3 of relay 26 normal, through the winding of relay 26 to battery. Relay 26 looks up through its contacts 2 to ground at contacts 2 of relay 22. The second set of impulses are stored by the switch 2UC as already indicated and relay 23 causes the partial operation of relay 27 through one winding and contacts 4 of that relay, contacts 5 of relay 25 operated and contacts 1 of relay 23 operated. When relay 23 restores relay 27 operates completely through both windings in series contacts 5 of relay 27 operated, to ground at contacts 2 of relay 22 operated. Contacts 3 of relay 27 open the operating circuit of relay 29 which operated when relay 25 operated from battery through the non-inductive winding of relay'29, contacts 3 of relay 27 normal, contacts 3 of relay 25 operated, the inductive winding of relay 29 to ground at contacts 2 of relay 22 operated. Relay 29 provides its own locking circuit through contacts 2 and does not, therefore, release when its operating circuit is opened by relay 27.

Contacts 1 of relay 27 open the impulsing circuit to prevent any further impulses being passed to the switch 2UC. Contacts 2 of relay 27 re-establish the driving circuit for the final selector through contacts 1 of relay 26 operated, contacts 2 of relay 27 operated and contacts 1 of relay 28 normal to ground. When the final selector reaches the set of contacts marked by the switch 2UC a circuit'is completed for relay 28 from battery contacts 3 of relay 26 operated, contacts 4 of relay 2K operated, the control wiper C and bank contact of the final selector through the strapping to the bank contact and wiper 2UC1 of the switch 2UC, contacts 3 of relay 29 operated, contacts 6 of relay 27 operated, contacts 4 of relay 26 operated, to ground. lVhen the relay 28 operates the driving circuit for the magnet 28 is opened and the locking circuit of relay 29 is transferred through contacts 1 of relay 29 operated, contacts 3 of relay 2K operated and .the winding of relay 2H to battery. Relay 2H locks up through its second winding and contacts 3 of relay 2H operated, contacts 2 of relay 2B operated to ground. The operation of relay 2H opens the circuit of relay 2K at contacts 1 and placesa ground on the test wire. Contacts 2 of relay 2H open the driving circuit of the magnet 2S and contacts4 and .5 complete the talking circuit to the called line or trunk. The circuit for relay 22 was opened at the same time as the circuit for relay 2K and when the former releases it opens the locking circuit of relays 25, 26, 27 and 29 and closes the homing circuit for the switch QUC and subsequently for the switch 2T0, over off-normal banks 2UC3 and 2TC3 as in the distributor switch. When the operator releases the circuit for relay 2A is opened causing the subsequent release of relays 2B and 2H, the switch does not restore to normal. It will be noted that if the last digit is 1 the marking wiper QUClof the switch QUC is connected to thevmarking wiper 2TC1 of the switch 2T0 and in consequence the group marking contacts on the bank of the offering final switch are thus used for the first lines of such groups.

As the final switch does not test the condition of the selected line to the test wiper T is left dead.

It is to be understood that the invention is not limited to the particular type and circuit arrangements of the conversation switches and control circuits described in detail;

Modifications falling within the scope of the appended claims will readily occur to those versed in the art. For example, instead of employing two marking switches in the con trol circuits for responding to the two series of impulses, respectively, a single switch may be used which responds successively to the two series of impulses and in accordance therewith first marks a group of lines and then a line within such group.

' What is claimed is:

1. A telephone system comprising a plurality of selector switches means associated Eli ' l 1 connecting said ortions tQ 'ELhQT.

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,2. A telephone system comprising a plurality of trunk offering final selector switches associated with a trunk operators position means associated with said switches by which any one is adapted to be associated with a busy line, the circuit of each of said final switches comprising an individual portion and a portion common to all of said final selector switches and means for operatively connecting said portions together.

3. A telephone system comprising aplurality of final selector switches means associated with said switches by which any one is adapted to be associated with a busy line, a plurality of trunk offering distributor switches associated with a trunk operators position any one of which is adapted to be operated to select one of said selector switches, and a control circuit adapted to be associated with said distributor switch to the exclusion of the other distributor switches and in response to transmitted impulses from said operators position to control the selective operation of said distributor switch.

4:. A telephone system comprising a plurality of trunk offering final selector switches associated with a trunk operators position means associated with said switches by which any one is adapted to extend a connection to a busy line, and a control circuit which is adapted to be associated with said final. switch to the exclusion of the other final switches and which in response to transmitted impulses from said operators position is adapted to control the selective operation of said final switch.

5. A telephone system as claimed in claim 3 comprising a relay individual to said distributor switch, and common conductors extending between said control circuit and each of said distributor switches, the control circuit being adapted tobe associated with said distributor switch over said common conductors by the operation of said relay. p

6. A-telephone system in accordance with claim 4 comprising a relay individual to said final switch, and common conductors extending between said control circuit and each of said final switches, said control circuit being adapted to be associated with said final switch over said common conductors by the operation of said relay.

7 A system in accordance with claim 5 wherein said control circuit comprises an auxiliary switch, said switch being adapted to respond to transmitted impulses and in accordance therewith to control. theoperation of said distributor switch.

8. A system in accordance with claim 4 wherein said control circuit comprises an auxiliary switch, said switch being adapted to respond to transmitted impulses and in accordance'therewith to control the operation of said final switch.

9. A system in accordance with claim t wherein said control circuit is adapted to be automatically disassociated from said final switch upon the completion of the operation of the latter and to be accessible of. use with another final switch.

10. A system in accordance with claim 3 

